Well tools



0st, 14, 1958 J. v.. FREDD 2,856,003

WELL TOOLS Filed Nov. 19, 1954 2 Sheets-Sheet 2 J: k V

. mmvroa. lo/7n I/ Freod ATTORNEY WELL TOOLS John V. Fredd, Dallas,Tex., assignor to Otis Engineering Corporation, Dallas, Tex., acorporation of Texas Application November 19, 1954, Serial No. 470,042

12 Claims. (Cl. 166-126) This invention relates to well tools, and moreparticularly to a locking means for securing well tools in well tubing.

An object of the invention is to provide a new and improved lockingmeans for securing well tools, such as well head plugs, in a desiredposition in well tubing.

Another object of the invention is to provide a locking means, of thetype described, having an expansible means for engaging the well tubingto lock the well tool thereto and a locking member for holding theexpansible means in expanded position.

Still another object of the invention is to provide a locking means ofthe type described, wherein the locking member cannot be moved tooperative position to hold the expansible means in expanded positionunless the expansible means is in fully expanded position.

A further object of the invention is to provide a locking means, of thetype described, for a well plug having a longitudinal bore and a valvefor closing said bore, the locking device being positioned by a runningtool which holds the valve open until the expansible means is locked infully expanded position.

A still further object of the invention is to provide a new and improvedwell plug for closing a well tubing which may be locked in a landingnipple of a particular configuration by an expansible means whichexpands to fully expanded position when disposed in the landing nipple,the expansible means being lockable in said expanded position by alocking member which cannot be moved to locking position until theexpansible means is in fully expanded position.

Another object of the invention is to provide a well. plug, of the typedescribed, having a packing means for.

sealing between the well tubing and the plug, and a longitudinal boreclosable by a valve, said valve being held open during the insertion andremoval of the well plug whereby the fluid pressure difierentials actingacross the plug may be equalized.

Additional objects and advantages of the invention will be readilyapparent from the reading of the following description of devicesconstructed in accordance with the invention, and reference to theaccompanying drawings thereof, wherein:

Figure 1 is a view, partly in elevation and partly in section, of thewell plug showing the same locked in position in a landing nipple of awell tubing;

Figure 2 is a similar view of a modified form of the well plug shown inFigure 1;

Figure 3 is a similar view of still another modified form of the wellplug shown in Figure 1, showing the same being lowered into place in awell tubing;

Figure 4 is a cross-sectional view taken on the line 4-4- Figure 6 is aperspective view of the expansible keys atent and locking member ofFigure showing the expansible keys in retracted position.

Referring now particularly to Figure 1, the numeral 10 designatesgenerally a well plug which includes a carrier mandrel 11 provided atits. upper end with a flange 12 having tangential grooves 13 forreceiving shear pins whereby the carrier mandrel may be detachablysecured to a suitable running tool (not shown). A tubular key or lockingmember carrier 14 is slidably mounted on the carrier mandrelintermediate the ends thereof and is provided on its upper end with anexternal annular undercut flange 15 whereby it may be engaged by asuitable pulling tool.

The key carrier 14 has an enlarged lower portion 16 provided withopposed apertures or windows 17 through which the bosses 18 and 19 .ofthe expansible keys 20 extend. The keys 20 are substantially T-shapedand are provided with upper and lower extensions 21 which are areenlarged at the upper end of the lock sleeve to pro-. vide lockingextensions 27 having opposed locking surfaces 28 which are adapted toextend between the keys 20 when the lock sleeve is in its upper lockingposition:

shown in Figures 1 and 5, wherein the locking surfaces 28 of the lockingextensions engage the inner lock sur faces 29 of the locking keys toprevent inward movement of the keys toward retracted position. The locksleeve is also provided with upwardly facing stop shoulders 30' at thelower ends of the locking surfaces 28, and these stop shoulders areadapted to engage the downwardly facing stop shoulders 31 on the underside of the arms of the upper cross portion of the T-shaped locking keysto.

limit upward movement of the lock sleeve with respect to the lockingkeys.

A packer mandrel 35 is threaded on the lower end of the lock sleeve andis rigidly secured thereto by a set screw 36. A packer assembly 37 isdisposed on the threaded on the lower end of the packer mandrel andupward movement of the packer assembly is limited by engagement of thepacker assembly with the enlarged upper portion 34 of the packermandrel.

The carrier mandrel and the packer mandrel have aligned longitudinalbores which are-closable by a valve 1 42 mounted in a valve cage 43threaded on the lower end of the packer mandrel. The valve has afrustoconical ground seating surface or head 44 which engages thebeveled surface or valve seat 45 at the lower end of the packer mandrelto plug the bore of the packer mandrel. A groove 46 in the valve seatingsurface receives an O-ring 47 which provides further sealing between theThis valve is biased upwardly 1 toward closed position by a spring 48disposed about the valve and whose opposite ends bear against adownwardly 1 facing shoulder 49 below the head of the valve and theupwardly facing shoulder 50 in the lower end of the bore valve and thevalve seat.

of the valve cage.

a landing nipple having an internal annular groove 61,

defined by internal flanges 62 and 63, of corresponding The keys areyieldably urged toward.-

The well tubing 40 includes or has connected therein configuration tothe upper bosses 18 of the keys 20. The upper and lower surfaces 64 and65 of the lower bosses 19 of the upper surface 66 of the upper bosses 18of the keys are .beveled, whereby the. keys are cammedinwardly uponmeeting internal obstructionsin the welltubing in passing .therethrough.Abrupt downwardly facing stop shoulders .67 at the lower. endof theupper bosses 18 of the keys extend substantially perpendicularly withrespect to-the longitudinal axis .Of'th well tool and of the welltribinglwherebywhen the keys reach a landing nipple 40 having theappropriate internal configuration the keys expand-"to the. positionsshown in Figure 1, wherein the stop shoulders 67 engage the annularupwardly facing :s top shoulderv '68 and. thus. limit. downward movementof the pluginthe-welltubingI i H ""In'u'se, the" well plug is loweredinto the well tubing by meansof a suit able.runningtool, having anannular skirt which r1 sepesaver.fian e 12 on the upper end of thecarrier mandrel and whi'ch is detachably secured to the carrier mandrel-l'ayfshearlpins which are received in the grooyes 13"in'the upperend'of said flange. The running tool sh'asapron'g which'extendsdownwardly through the carrier mandrel and the passer. mandrel toengage-the upper end of lthevalvel and hold it in lowered openposition'against the upward'force'exerted by the valve spring 48. Withthe valve-42 open, the plug may be moved downwardly in the welltubingeven though liquids are present insaid well tubing. t

The wellplug is moved downwardly in the well tubing with the keys movinginwardly upon meeting obstructions until a landing nipple 60 .of theappropriate internal configuration is reached, whereupon the lockingkeys 20 move to fully expanded positionand. the engagement of thes'topshoulders 67 of the upper bosses of the keys and the stop.shoulder68 of the landing nipple prevents further downward movement of the wellplug.

The carrier mandrel is then pulled upwardly to move the upwardextensions 27 of the locksleeve between the keys to l'ockthe keys in theirexpanded position, the. engagementbetween the upwardly'fa'cing beveledshoulders 64'a'nd, 66 of the keys and the'downwardly facing beveledshoulders 72 and'73 of the landing nipple tending to hold the keysstationary duringthis upward movement of the carrier'ma'ndrel. The widthof the upward extensions of the lock sleeve is such that they cannot bemoved upwardly between the keys unless the latterareexpanded to themaximum limit in the landing nipple, so thatthe plug is positivelylock'ed'in the mahdrel before the valve is closed to jcrea'te'a'pressur'e 'differential'acrossthe plug. This feature is of greatimportance in safeguarding human lives and'well equipment's incethe'great pressure differentials found in the wells could unseat theplug and move it upwardly with great force if the locking keys are notin fully expanded'position when the valve 42 is closed.

The running 'tool'is then moved upwardly with respect to the carriermandrel, the shear pins which connect the running 'tool to the carriermandrel shearing. Simultaneously, the prong of therunning'tool movesupwardly permitting the valve 42 to close. The well'plug is now lockedinoperative position in the well tubing. The running tool is thenremoved. I

When it is desired to remove the well plug, a pulling toolfsuch as theone disclosed in'thepatent to H. C. Otis, 1,898,261, islower ed into'thewell tubing. The pulling tool may-beprovided Witha-prong which entersthe carrier mandrel and' the packer mandrelto engagethe upper end ofthevalve 42'to open the valve and thus equalize the pressure differentialon the well plug. If desired, the pressure difiereritial across thewellplug could be reduced by introducing pressure to the bore'ofthetubing string above the well plug from an external source of fluidpressure. The pulling tool, once the pressure differential is removed,engages the upper end of the carrier mandrel and drives it downwardly,thus moving the upward extensions 27 of the lock sleeve downwardly outfrom between the locking 7 keys. an f eein t y for inward movementtoward retracted position. The pulling tool then engages the undercutflange 15 at the upper end of the key carrier and the latter is pulledupwardly. The locking keys move inwardly toward retracted positionduring this upward movement of the well plug due to the camming actionbetween the upwardly facing beveled upper surfaces 64 and 66 of the keysand the downwardly facing beveled shoulders 72 and 73 of the landingnipple. The well plug is then pulled upwardly from the well tubing, thecamming action of the beveled surfaces 64 and 66 moving the keys inwardly upon encountering obstructions in the well tubing.

It will be apparent that a new and improved locking means for well plugsand the like has been illustrated and described, which includesexpansible locking keys which move into fully expanded position whenpositioned in a landing nipple of a suitable configuration, and alocking sleeve or member which is movable upwardly between the keys tolock them in their expanded position when the keys are in fully expandedposition. It will also be apparent that a new and improved well plughasbeen illu'stratedand described which includes a valve which is closableonly when the well: plug is securely locked in position in the welltubing.

In Figure 2 is illustrated a modified wellplug which is adapted to belocked in position in a landing nipple or adaptor 81- of a well tubing82. The well plug includes a carrier mandrel 83 on which is slidablymounted the key carrier 14. The keys 20 extend throughthe windows 17 ofthe key carrier and are adapted to engage in the key recesses 84 and85-of the adaptor 81. In this form of the well plug, the packer mandrel86 is directly threaded to the lower end of the carrier mandrel and thelock sleeve arms 87 are integral with and project upwardly from theupper end of the packermandrel and along the carrier mandrel. The arms87 are rigidly secured to the carrier mandrel by a set screw 88. Thelock sleeve arms define the same slots 26 and have the same upwardextensions 27 as the lock mandrel 25 of Figure l.

A packer assembly 89 of thechevron or V-typeis held on the packermandrel 86 by a nut 90 threaded thereon. A valve cage 91 is threaded onthe lower .end of the packer mandrel and has a main valve 92 mountedtherein which seats against the beveled shoulder or seat 93 at the lowerend of the packer mandrel. The main valve is biased upwardly towardclosed position by a spring 94 whose opposite ends bear against .theshoulders 95 and 96 of the main valve and thevalve cage, respectively.

The main valve is provided with a secondary valve 97 which engages avalve seat 98 in the central bore of the main valve to close the latter.The secondary valve is biased toward closed position by a spring 99 inthe bore of the main valve and is provided with an upward extension 100which projects upwardly above the upper end of the main valve when thesecondary valve is in closed position. The main valve 92 has a lowersection 101 threaded in the upper section 102 to provide a seat for thespring 99. The upper and lower sections of the main valve havecommunicating bores which are closed against upward flow therethrough bythe secondary valve 97.

The well plug 80 is used and operated in the same manner as the wellplug 10 except that the secondary valve is first opened by the prong ofthe pulling tool before the main valve is opened preparatory to removalof the plug. The provision of the secondary valve, which closes asmaller orifice and can therefore be opened by a relatively smalldownward force, enables the well plug to be removed easily from wellswherein extremely high pressure differentials exist across the wellplug.

The well plug of Figure 3 difiers from the well plug 80 of Figure 2 onlyin having a dilferent form of valve for closing the bore of the packermandrel 86. The main valve 111 is mounted in a valve cage 112 threadedon the lower end of the packer mandrel and includes an upper section 113which sets against the valve seat 93:

provided in the lower end of the packer mandrel. A lower sleeve section114 is disposed about the lower reduced end 124 of the upper section 113of the main valve and a spring 115 disposed about the lower sleevesection is confined between an upper external flange 116 of the sleevesection and a shoulder 117 of the valve cage to bias the main valveupwardly toward closed position.

An inner secondary valve 118 is disposed in the lower sleeve section andis adapted to engage a beveled seat 119 at the lower end of the uppersection 113 to seal the bore thereof. An upward extension 120 on thesecondary valve extends upwardly through the bore of the upper sectionof the main valve and projects above the upper end thereof when thesecondary valve is in closed position. A spring 121 is confined betweenthe lower end 122 of the secondary valve and a shoulder 123 of the lowersleeve section to bias the secondary valve toward closed position.

The landing nipple 60 and the adaptor 81 illustrated and describedherein are shown to be in the form of well head fittings or tubinghangers for use in well-known types of well heads for supporting thestring of tubing or flow conductor in the well bore.

It will readily be seen that new and improved well plugs have beenillustrated and described, each of which includes a carrier mandrel, akey carrier provided with outwardly biased locking keys slidably mountedon the carrier mandrel, a lock sleeve rigidly secured to the carriermandrel for locking the keys in fully expanded positions upon upwardmovement of the carriermandrel relative to the keys, 2. packer mandrelsecured to the carrier mandrel, and a valve for closing the longitudinalcommunicating bores of the carrier and packer mandrels, the valve beingbiased toward closed positions. It will also be apparent that in twoforms of the well plug, the main valve is provided with a secondaryvalve also biased toward closed position and which is operable initiallyby a prong of a pulling tool to relieve the pressure differential acrossthe well plug preparatory to its removal from the well.

Furthermore, it will be seen that, in all forms of the well plugs, theinner locking surfaces of the locking keys are so designed andproportioned with respect to the upper extensions of the lock sleeves orlock sleeve arms that said lock sleeves or arms cannot be moved upwardlyto hold the locking keys in expanded position unless and until the keysare expanded to the maximum possible dirameter within the recesses orgrooves of the landing nipple. This provides for positive assurance thatthe well plug is properly locked in place in the landing nipple beforethe running tool is released therefrom and before pressure differentialis applied across said well plug. Likewise, the locking mechanismcannotbe released without first driving the carrier mandrel and lock sleevedownwardly, thus precluding the possibility of unlocking the well plugit any appreciable pressure diflerential exists across the packing ofsaid well plug.

It is believed obvious that the carrier mandrel may be composed ofseveral separate parts suitably connected together to form a unit, forexample, the mandrels 11 and 83, and the lock sleeve 25 and the packermandrel 86 having the lock sleeve arms 87 thereon.

The foregoing description of the invention is explanatory only, andchanges in the details of the constructions illustrated may be made bythose skilled in the art, within the scope of the appended claims,without departing from the spirit of the invention.

What I claim and desire to secure by Letters Patent 1. A well toolincluding: a well head fitting having a bore therethrough and havingmeans for connecting it at its lower end to a well fiow conductor, saidfitting having an internal groove in its bore providing an upwardlyfacing stop shoulder and a downwardly facing lock shoulder in said bore;a carrier mandrel; locking means slidably .8 mounted on said carriermandrel and movable longitudinally thereon; said locking means having adownwardly facing stop shoulder thereon and an upwardly facing lockshoulder, said locking means being movable laterally of said carriermandrel between retracted and expanded positions; means biasing saidlocking means outwardly toward expanded positions; said locking meansbeing free to move toward fully expanded position at all times andadapted to enter the groove in said fitting whereby the stop shoulder onsaid locking means engages the stop shoulder in the bore of the fittingto limit downward movement of the locking means therethrough and toposition said locking means in alignment with said groove, whereby saidmeans biasing said locking means outwardly may move said lock shoulderof said locking means to position to engage said lock shoulder in thebore of said fitting; and lock means on said carrier mandrel movableupwardly with said carrier mandrel into engagement with said lockingmeans when said locking means is in fully expanded position to lock saidlocking means in expanded position upon such upward longitudinalmovement of said carrier mandrel relative to said locking means.

2.v A well took including: a well head fitting having a boretherethrough and having means for connecting it at its lower end to awell fiow conductor, said fitting having an internal groove in its boreproviding an upwardly facing stop shoulder and a downwardly facing lockshoulder in said bore; a carrier mandrel; locking means slidably mountedon said carrier mandrel and movable longitudinally thereon; said lockingmeans having a downwardly facing stop shoulder thereon and an upwardlyfacing lock shoulder, said locking means being movable laterally of saidcarrier mandrel between retracted and expanded positions; means biasingsaid locking means outwardly toward expanded position; said lockingmeans being free to move toward expanded position at all times andadapted to enter the groove in said fitting whereby the stop shoulder onsaid locking means engages the stop shoulder in the fitting to limitdownward movement of the locking means therethrough, and to positionsaid locking means in alignment with said groove whereby said meansbiasing said locking means outwardly may move said lock shoulder of saidlocking means to position to engage said lock shoulder of said fitting;lock means on said carrier mandrel movable upwardly with said carriermandrel into engagement with said locking means when said locking meansis in fully expanded position to lock said locking means in expandedposition upon longitudinal upward movement of said carrier mandrelrelative to said locking means; said carrier mandrel having meanscarrying a packing assembly below said locking means.

3. A well tool including: a well head fitting having a bore therethroughand having means for connecting it at its lower end to a well flowconductor, said fitting having an internal groove in its bore providingan upwardly facing stop shoulder and a downwardly facing lock shoulderin said bore; a carrier mandrel; locking means slidably mounted on saidcarrier mandrel and movable longitudinally thereon; said locking meanshaving a downwardly facing stop shoulder thereon and an upwardly facinglock shoulder, said locking means being movable laterally of saidcarrier mandrel between retraded and expanded positions; means biasingsaid locking means outwardly toward expanded position; said lockingmeans being free to move toward expanded position at all times andadapted to enter the groove in said fitting whereby the stop shoulder onsaid locking means engages the stop shoulder in the fitting to limitdownward movement of the locking means therethrough, and to positionsaid locking means in alignment with said groove whereby said meansbiasing said locking means outwardly may move said lock shoulder of saidlocking means to position to engage said lock shoulder of said fitting;lock means on said carrier mandrel movable upwardly with said carriermandrel into engagement with said locking means when said locking meansis in fully expanded position to lock said locking means in expandedposition upon longitudinal upward movement of said carrier mandrelrelative to said locking means;.said carrier mandrel having meanscarrying a packing assembly below said locking means and disposed toengage and seal against the bore wall of the well flow conductor belowsaid fitting.

4. A well tool including: a well head fitting having a boretherethrough'and having means for connecting it at its lower end to awell flow conductor, said fitting having an internal groove in its boreproviding an upwardly facing stop shoulder and a downwardly facing lockshoulder in said bore; a carrier mandrel; locking means slidably mountedon said carrier mandrel and movable longitudinally thereon; said lockingmeans having a downwardly facing stop shoulder thereon and an upwardlyfacing lock shoulder, said locking means being movable laterally of saidcarrier mandrel between retracted and expanded positions; means biasingsaid locking means outwardly toward expanded position; said lockingmeans being free to move toward expanded position at all times andadapted to enter the groove in said fitting whereby the stop shoulder onsaid locking means engages the stop shoulder in the fittingto limitdownward movement of the locking means therethrough, and to positionsaid locking means in alignment with said groove whereby said meansbiasing said locking means outwardly may move said lock shoulder of saidlocking means to position to engage said lock shoulder of said fitting;lock means on said carrier mandrel movable upwardly' with said carriermandrel into engagement with said locking means when said locking meansis in fully expanded position to lock said locking means in expandedposition upon longitudinal upward movement of said carrier mandrelrelative to said locking means; said carrier mandrel having meanscarrying a packing assembly below said locking means and disposedto-engage and seal against the bore wall of the well flow conductorbelow said fitting, said well tool having a bore therethrough from belowsaid packing assembly to above the'locking means.

5. A well tool including: a well head fitting having a bore therethroughand having means for connecting it at its lower end to a well flowconductor, saidfitting having an internal groove in its bore providingan upwardly facing stop shoulder and a downwardly facing lock shoulderin said bore; a carrier mandrel; locking means slidably mounted on saidcarrier mandrel and movable longitudinally thereon; said locking meanshaving a downwardly facing stop shoulder thereon and an upwardly facinglock shoulder, said locking means being movable laterally'of saidcarrier mandrel between retracted and expanded positions; means biasingsaid locking means outwardly toward expanded position; said lockingmeansbeing free to move toward expanded position at all times andadapted to enter the groove in said fitting whereby the stop shoulder onsaid locking means engages the stop shoulder in the fitting to limitdownward movement of the locking means therethrough, and to positionsaid locking means in alignment with said groove whereby said meansbiasing said locking means outwardly may move said lock shoulder of saidlocking means .to position to engage said lock shoulder of said fitting;lock means on said carrier mandrel movable upwardly with said carriermandrel into engagement with said locking means when said locking meansis in fully expandedposition to lock said locking means in expandedposition upon longitudinal upward movement of said carrier mandrelrelative to said locking means; said carrier mandrel having meanscarrying a packing assembly below said locking means anddisposed toengageand seal against thebore wall of the well flow conductor belowsaid fitting, said well tool having a bore therethrough from below saidpacking assembly to above the locking means; and an openable andclosable valve means normally closing-said bore.

6. A welltool including: a well head fittinghaving a bore theret'hroug'hand having means 'for connecting it at its lower end to a well flowconductor, said fitting having an internal annular groove in its boreproviding an upwardly facing stop shoulder and a downwardly facing lockshoulder in said bore; a carrier mandrel; locking means slidably,mounted on said carrier mandrel and movable longitudinally'thereon;said locking means having a downwardly facing stop shoulder thereon andan upwardly facing lock shoulder, said locking means shoulders beingmovable laterally of said carrier mandrel between retracted andprojected positions; means biasing locking means outwardly towardprojecting position, said locking means being free to move toward fullyprojected position at all times; said locking means being adapted toenter said fitting whereby the stop shoulder on said lockingmeansengages the stop shoulder in the bore of said fitting'to limit downwardmovement of said locking means therethrough and to position said lockingmeans in alignment with said groove whereby said means biasing saidlocking means outwardly may move said lock shoulder of said lockingmeans to projecting position for engaging said locking shoulder in saidfitting; and lock means on said carrier mandrel movable up wardly withsaid carrier mandrel into position engaging said locking means toprevent retraction of said locking means from projecting position,whereby said well tool is locked in position insaid well head fitting.

7. A well tool including: a well head fitting having a' boretherethrough andhaving means for connecting it at its lower end to awell fiow conductor, said fitting having an internal annular groove inits bore providing an upwardly facing stop shoulder and a downwardlyfacing lock shoulder in said bore; a carrier mandrel; locking meansslidably mounted on said carrier mandrel and movable longitudinallythereon; said locking means having a downwardly facing stop shoulderthereon and an upwardly facing lock shoulder, said locking meansshoulders being movable laterally of said carrier mandrel betweenretracted and'projected positions; means biasing said locking meansoutwardly toward projecting position, said locking means being free tomove toward fully projected position at all times; said locking meansbeing adapted to enter said fitting whereby the stop shoulder on saidlocking means engages the stop shoulder in the bore of said fitting tolimit downward movement of said locking means therethrough and toposition said locking means in alignment with said groove whereby saidmeans biasing said locking means outwardly may move said lock shoulderof said locking means to projecting position for engaging said lockingshoulder in said fitting; and lock means on said carrier mandrel movableupwardly with said carrier mandrel into position engaging said lockingmeans to prevent retraction of said locking means from projectingposition, whereby said well tool is locked in position in said well headfitting; said carrier mandrel having means carrying a packing assemblybelow said locking means.

8. A well tool including: a well head fitting having a bore therethroughand having means for connecting it at its lower end to a well flowconductor, said fitting having an internal annular groove in its boreproviding an. upwardly facing stop shoulder and a downwardly facing lockshoulder in said bore; a carrier mandrel; locking means slidably mountedon said carrier mandrel and movable longitudinally thereon; said lockingmeans having a downwardly facing stop shoulder thereon and anupwardly'facing lock shoulder, said locking means shoulders beingmovable laterally of said carrier mandrel between retracted andprojected positions; means biasing said locking means outwardly towardprojecting position, said locking means being free to move toward fullyprojected position at all times; said locking means being adapted toenter said fitting whereby the stop shoulder on said locking meansengages the stop shoulder in the bore of said fitting to limit downwardmovement of said locking means therethrough and to position said lockingmeans in alignment with said groove whereby said means biasing saidlocking means outwardly may move said lock shoulder of said lockingmeans to projecting position for engaging said locking shoulder in saidfitting; and lock means on said carrier mandrel movable upwardly withsaid carrier mandrel into position engaging said locking means toprevent retraction of said locking means from projecting position,whereby said well tool is locked in position in said well head fitting;said carrier mandrel having means carrying a packing assembly below saidlocking means and disposed to engage and seal against the bore wall ofthe well conductor below said well head fitting, said carrier mandreland means carrying said packing assembly having a bore therethrough frombelow said packing assembly to above said locking means.

9. A Well tool including: a carrier mandrel, a pair of locking meansdisposed on opposite sides of said carrier mandrel and mounted on saidcarrier mandrel for longitudinal movement relative thereto, said lockingmeans being movable outwardly of said carrier mandrel to expandedpositions; means biasing said locking means toward said expandedpositions; said locking means being free to move toward fully expandedpositions at all times; and lock means on said carrier mandrel movableto a position between said locking means only when said locking meansare in fully expanded positions; said lock means when in such positionbeing disposed to engage and lock said locking means in said expandedpositions.

10. A well tool including: a carrier mandrel, a pair of locking meansdisposed on opposite sides of said carrier mandrel and mounted on saidcarrier mandrel for longitudinal movement relative thereto, said lockingmeans being movable outwardly of said carrier mandrel to expandedpositions; means biasing said locking means toward said expandedpositions, said locking means being free to move toward fully expandedpositions at all times; lock means on said carrier mandrel movable to aposition between said locking means only when said locking means are infully expanded positions; said lock means when in such position beingdisposed to engage and lock said locking means in said expandedpositions upon upward movement of said carrier mandrel relative to saidlocking means; said carrier mandrel having a longitudinal 10 bore; avalve for closing said bore; and means biasing said valve toward closedposition.

11. A well tool including: a carrier mandrel having an upper necksection and a lower lock section; cage means slidable longitudinally onsaid neck section of said mandrel; a pair of laterally movable lockingmeans carried by said cage means on opposite sides of said neck sectionof said mandrel and movable outwardly of said mandrel to expandedpositions; means biasing said looking means toward expanded position;said locking means being free to move toward fully expanded positions atall times; and lock means on said mandrel disposed to engage saidlaterally movable locking means to hold said locking means in expandedposition, said lock means being movable with said mandrel longitudinallyupwardly of said cage means to a position engaging saidlocking meansonly when said locking means are fully expanded.

12. A well tool including: a carrier mandrel; locking means mounted onsaid carrier mandrel and movable laterally thereof between retracted andexpanded positions; means biasing said locking means toward expandedpositions; said locking means being free to move toward fully expandedpositions at all times; and lock means mounted on said mandrel anddisposed to engage said laterally movable locking means to hold saidlocking means in expanded position, said lock means and said lockingmeans each having longitudinally disposed locking surfaces co-engageableto positively hold said looking means in expanded position anddisengageable upon downward movement of said lock means longitudinallywith respect to said locking means to permit said locking means to moveto retracted position, said lock means being movable upwardly to aposition wherein the coengageable locking surfaces of said lock meansand said locking means are engaged to hold said locking means inexpanded position, such upward movement being possible only when saidlocking means is in fully expanded position.

References Cited in the file of this patent UNITED STATES PATENTS2,139,983 Stone Dec. 13, 1938 2,392,244 Hooser Jan. 1, 1946 2,401,119Taylor May 28, 1946 2,447,546 Spencer Aug. 24, 1948 2,605,843 Baker Aug.5, 1952 2,673,614 Miller Mar. 30, 1954 2,681,112 Lee June 15, 1954

